I don't know if you guys have seen this yet, but I wanted to show you a 64k demo.
http://www.pouet.net/prod.php?which=10545
It is called Zoom 3. It has per pixel lighting and shadow volumes.
You will need a video card that supports shaders. That would be a Geforce 3 and up, or an ATI Radeon 8500 and up.
It says you need an NT based Windows, but ME worked. It just didn't have the voice.